HashMap (hash, dictionary, associative array) in Rust

HashMap in Rust is a data-structure holding key-value pairs. Similar to hash in Perl and in other languages, dictionary in Python, and associative arrays in PHP, just to name a few.

Learn the basics about HashMap in Rust

• Create empty HashMap and insert key-value pairs - new, insert, mut.
• Create empty HashMap in Rust without type definition.
• Initialize immutable HashMap with data - from, keys, values.
• Check if key exists in HashMap - if the HashMap contains the key - contains_key.
• Given a key, get value from a HashMap - get, Option, match.

Some more advanced topics aboit HashMap in Rust

• Convert hash to hash in Rust

• Pass a mutable hash to a function in Rust

• Rust HashMap where tuples are the keys

• Serialize and deserialize HashMap to JSON in Rust

Uses of HashMap

• Embedding simple CSV file in Rust application
• Count distribution of values - how many times each word appears in a list of words